I learned some stuff about hippos today

[Rain Man]

When I was in Africa, we went to an estuary that had a bunch of hippos. The interesting thing that I learned is that they don't swim. When they move in a river, they sink down to the bottom and do a "leap and glide" that seems pretty efficient. When we saw a hippo moving, we could trace its path because every 50 feet or so there would be a small muddy patch in the water where the hippo had kicked off the bottom.